Photo-electric control system for pipe organs



J. H. HAMMND. JR

Mgrch 26, 1929.

PHOTC ELECTRIC CONTROL SYSTEM FOR P IPE ORGANS e sheets-sheet 1 FiledApri1'14. 1924 I5 A ORNEY wf *im uns March 26, 1929. J. H. HAMMOND. JR

PHOTO ELECTRIC CONTROL SYSTEM FOR PIPE RGANS Filed April 14, 1924 6Sheets-Sheet 2 NNN IJNVENTOR ft Td/mdf Hl ATTORNEY March 26, 1929. J, HHAMMOND, JR 1,706,731

PHOTO ELECTRIC CONTROL SYSTEM FOR PIPE ORGANS Filed April 14. 1924 '6sheets-Sheet 3 INVENTOR HIS ATTORNEY March 26,y 1929. J. H. HAMMOND, JR

PHOTO LECTRIC CONTROL SYSTEM FOR PIPE ORGANS Filed April 14, 1924 6Sheets-Sheet 4 INVENTOR met @WN 05N NWN MN March 26, 1929. J. H.HAMMOND, JR

PHOTO ELECTRIC CONTROL SYSTEM FOR PIPE ORGANS Filed April 14, 1924 6sheets-Sheet 5 kwmV www- INVENTOR MM H15 ATTORNEY March '26 1929.v J. H.HAMMOND. JR

PHOTO ELECTRIC CONTROL SYSTEM FOR PIPE ORGANS Filed April 14. 1924 6Sheets-Sheet 6 QE .Mal

Q "in WN Y ANN www @GN no@ INVENTOR Patented Mar. 26, 1929.

UNITED STATES 1,766,731 PATENT OFFICE.

JOHN HAYS HAMMOND, JR., OF GLOUCESTER, MASSACHUSETTS.

PHOTO-ELECTRIC CONTROL SYSTEM FOR RIPE OBJGANS.

Application iled April 14,

Some of the objects of this invention are to provide means for'playingan organ 1n synchronism with a moving picture lm and to provide meansfor automatically impressing on a circuit a plurality of frequencies,the resultant of which causes a variation 1n "the intensity-of a beam oflightwhich aflmusic was being played in, at the time that the filmbroke.

@ther objects will appear from the following description 'taken inconnection with the accompanying drawings in which Figure 1 isa.diagrammatic view of a system constructed so as to automaticallyproduce a plurality of frequencies, the resultant of which affects theintensity of a beam of light which strikes a photographic film; Fig. 2is a diagrammatic view of a system con structed so as to cause thatportion of the photographic film which was affected by the beam of lightto reproduce the original frequencies which operate a number of tunedcircuits; F ig. 3`shoWs diagrammatically a tone chamber anda swellshutter; Fig. 4 is a diagrammatic View of a system constructed so as toproduce .the synchronous operation of a motion picture lm and a rollofvperforated papel; for playing a pipe organ or other musicalinstrument; Fig. 5 is a modied form of the system of F igj2, arrangedfor playing chords should theV film be broken, and for automaticallyselecting the same key as that of the music; and Figure 6 is amoditiedform-of the structure of Figure 2.V Referring to theaccompanying drawings,

and principally to Figure 1, one embodiment of this inventioncomprises acontrol system 10, a relay mechanism 11, a plurality of vibratingsystems 12, which are controlled by the relay systemV 11 andWhichoper'ate a sensitive galvanometer 13 which controls a .beam-0flight from a. source of illumination 14'and projects it through a lightvarying means 15 onto a film 16 which is fed fromA a motion picturecamera 17.

passes over conductors 32.

'1924. serial No. 706,245.

The control system 10 consists of two strips of perforated paper 21 and22 which are wound upon rolls 23 and 24, 25 and 26 respectively. Thesestrips of paper pass over tracker bars 26 and 27 which are provided witha plurality of holes 28. The rolls 24 and 26 are driven by any suitablemeans, not shown, such as that employed in standard player mechanismsfor pianos, etc., thus causing the strips of paper 21 and 22 to bemovedover the tracker bars 27 and 26 at a uniform rate. Any suitable systemfor synchronizing the motion of these paper strips ymay be used, forexample, as that shown in my copending application, 551, filed April 19,1924.

The holes in the tracker bar 26 are con nected by tubes 30 to thepneumatic relay mechanism 11 which may be of any Wellknown standardconstruction. 1When air is admitted to any one of the tubes 3() it willcause a circuit to be closed through the corresponding terminal 31, .andthus current The holes in the. tracker bar 27 are connected by pipes 34tey Serial No. 707,-

.the relay mechanism 11. and control the cir- 4'cuit from the terminals35 through conductors 36, 37, 38, 39 and 40 respectively to thelvibrating mechanisms v12. Each of these .mechanlsms conslsts of amagnet 43, one end of the .windings of which 1s connected respectivelylto the conductors 40, 39, 38, y37, 36 and 32. The other ends of thewindings are connected by a conductor 44 which is connected to one poleof the battery 45, the other pole of which is connected by a conductor46 to the terminal 47 which in turn is connected Vto `the `common returnof the relay mechanism 11. Each magnet 43 is provided with an armature45 which is held in its retracted position, as shown by means of aspring 46', and a front contact with whichy the respective armaturemakes contact When in its operated position. The armature 45 isconnected by a conductor 47 to one pole of a battery 48, the

lother pole of which is connected by a conductor 49 to one terminal of acoil 50, wound `upon one leg of a tuning'fork 51. The other terminal ofthe coil 50 is connected by a conductor 52 to a contact 53 which isengaged by the armature'45 when the magnet 43 is energized.'llheconduetor 52 is connected by a branch conductor k55 to a microphonebutton v56 which in turn is connected to the other leg of the tuningfork.' The base ofthe tuning fork 51 is connected by a conductor 60 toone end of a primary winding of the transformer 61, the other end ofthis winding being connected by a conductor 62 to the con- 'ductor 49.One end of the primary winding of the transformer 61 is connected to oneend of a winding 63 wound around an armature 64. The other end of thewinding 63 is connected by a conductor 65 to one terminal of a condenser66, the other terminal of which is connected to one terminal of aprimary winding of a transformer 67, the other terminal of the windingof which is connected to the primary Winding of the transformer 61'. Onel5 terminal of the secondary winding of the transformer 67 is connectedby a conductor 70 to a conductor 71, and the other terminal of thesecondary of the transformer 67 is Connected by a conductor 72 to aconductora 73. The conductors 7l and 73 are connected to the coil of thesensitive galvanometer 13 which carries a small mirror 75. This mirrorreflects the light from the light produc'- ing source 14, which consistsof any suitable lamp 76, the rays of which pass through a lens system77, to a screen 78 which is made of suitable transparent material and isoonstructed so that the amount of light which it allows to pass throughit varies-as the beam is shifted from one end to the other of thescreen. The beam of light after leaving the screen 78 is focused by alens 79 upon the moving picture ilm 16. As the mirror 75 is rotated fromone extreme position to the other it will-cause a variation theintensity of the beam of light striking the photographic film fromamaximum to a minimum depending upon the strength of currentl in the coilof the galvanometer 13. The film 16 is wound upon two rolls 81 and 82and passes through the standard motion picture camera. 17. To the crank83 of the camera is secured a gear84 which meshes with a second gear` 85which rotates about the axis 86. Secured to the gear 85 is a bevelledgear 87 which meshes with a bevelled pinion 88 rigidly secured to oneend of the shaft 89. The other ,end of the shaft 89 carries a similarbevelled pinion 90 which meshes with a beveled gearl 91 secured to aAdrum 92 provided with. teeth 93 which engage suitable depressions in asecond drum 94 between-Which passes the film 16.

Pivoted to the camera 17 is an arm 96 which carries at its lower end adrum 97 over which passes the film 16, and at its upper end is connecteda spring 98, the other end of which issecured to a pin 99 fastened tothe side of the camera 17.

The system shown in Fig. 2 consists of a standard type of motion pictureprojector 101 provided with a film 102 which is rolled upon spools 103and 104 and passes over a toothed drum 105. This drum is provided 5 witha beveled gear 106. which meshes with a beveled pinion 107 secured to ashaft 108, the 'other end of which carries a similar bev'- eled pinion109, meshing with a beveled gear 110 rigidly secured to the crank 111which operates the projector 101.

Located adjacent to the film 102 is a suitable source -of illumination115, the light from which is focused by means f a lens system 116 on tothe film 102 on e other side of which is located a-photo electric cell117, one terminal of which is connected to a battery 119, theotherterminal of which is connected by a conductor 120 to the primarywindings of a plurality of transformers 121 to 126, etc. connected inseries. The return circuit from these transformers includes a conductor127 to the photo electric cell 117. The secondary windings of thetransformers 121 to 126 are connectedto suitable wave` filters 130 whichare inductively connected by transformers 131 to the input circuit of anamplifying system 132, the output circuits of which control relays 133to 138, etc.

The armatures of these relays are connected by conductors 140 to abattery 141. The retogether inspaced parallel relation by strips 303,304, 305. The strip 305 extends upwardly and is operatively connectedwith the swell shutter motor 301. A pair yof spaced guides 306, 306, isprovided for maintaining the strips 302 againstthe face of the chest.The strips 302 normally cover a Acorresponding plurality ,of slotssuchas 307.V

It will be seen that upon the actuation of the swell shutter motor 301,the slots 307 are uncovered. TheA shutter strips'302 are preferablyfaced with a layer of felt for deadening the sound. Y The relays 135 and136 control circuits through conductors 149 and 150 extending to theprimary note action 310 of the organ, and the notes are thus soundedwhen the respective circuits .are closed. Similarly, relays 137 and 138control circuits through conductors 153* and 154 which are connected .tothe primaryL stop action 311 of the organ, to control the operation ofthe various stops of the organ. The return '-current from all thesecircuits includes a common conductor 156 to the battery 141Y It will beunderstood that in practice a suiicient number of sets of band lters,am-

llO

plifyingcircuits relays, etc. each duplicates i so as to produce thedesired music, the notes, for example, being cut on the strip 22 and thecontrol of the stop action, swell shutters, etc. cut on the roll 21 (asshown in my co-pending application hereinbefore referred to). As thesepaper strips pass over the tracker bars 26 and 27 they will allow air toenter the pipes 30 and 34 whenever a perforation in the paper comesopposite a hole in the tracker bar. This will operate the relaymechanism 11 to close the corresponding circuit throughthe conductors32, 36, 37, 38, 39 and 40 as the case may be. Suppose, for example, thatthe circuit is closed through the conductor 40, thus energizing themagnet 43 which places the field magnetizing coil 50 across the battery48 which is also thrown across the primary of the input transformer 61and in series with the microphone buttons 56.. This causes the timingfork 51 to vibrate at its natural frequency which sets up oscillationsin thc resonant circuit composed of the coil 63, condenser 66 and theprimary of the transformer 67, and the secondary of the transformer 61.This causes current of the frequency of the tuning fork 51 to besupplied to the conductors 71 and 73 from the secondary of thetransfornnr This current, passing through the coil of the sensitivegalvanometer 13 causes the mirror 75 to vibrate at the same frequency asthe tuning fork 51. If a circuit is closed through the conductor 39 a`similar action will take place in the next audio oscillator, producinga current of' a slightly different frequency from that produced by thetuning forkP 51, as the tun` ing forks of the various4 vibrating systems12 are timed to slightly different frequencies so that each hole of thetracker bars` 36 and 37 when exposed by the perforation in the paperwill produce a frequency of a predetermined pitch in the circuit 71, 73thus causing the mirror 75 of the sensitive galvanometer to vibrate at afrequency which is the resultant of all of the combined frequencies ofthe circuits which may be closed at any given instant. This resultantfrequency causes the beam of light from the light source 76 to vibrateback and forth across the screen 78 thence` through the lens 79 to a.point on the film 16, the intensity of this light depending upon theplace on the screen 78 through which thc beam of light passes at. thatinstant. The beam of light which strikes the film 16 will therefore bevaried in intensity an amount proportional to the vibrations of themirror 75, and therefore to the. resultant frequency produced in thecircuit 71, 73 so thatl there will be produced on the film a narrowstrip, the. transparency of which varies according to this resultantfrequency.

Thev film 16 is moved past the point'where the beam of light strikes itat a uniform rate by rotation of the drum 92 which is driven by thegeartrain 84, 85, 87, 88, 90, 91 from the crank handle 83 of the motionicture camera 17. The film 16 will there ore move in synchronism withthis handle, which is turned manually at a uniform rate by the operator,taking the picture. As the film 16 is fed out. of the camera 17intermittentlypthe drum is provided for taking up this slack so that thefilm will be fed continually between the rolls 92 and 94,

In this manner a picture and the record from thc beam of light areimpressed on the film synchronously, the. operator controlling themotion of the paper strips 21 and 22 being able to control the motion ofthese music rolls 21 and 22 so that they will be in exact synchronismwith the taking of the moving picture, this being neressa ry so as toproduce the desired effect when the picture is to be shown at anytheatre at any future time.

l-Vhen the film is pnt into the projector 101 it is fed from tir roll103 in an intermittent manner by the operation of the crank 111. Thiscrank by means of the gear train 110, 109, 107 and 106 causes the uniforni rotation of the drinn 105. This feeds the film 102 at a nnifo; mrate in front of the beam of light prodiued by the light source 115,this beam of light being focused upon the narrow strip on the filmcontaining the record produced by the beam of light refiectefi from themirroi its. The amount of light 1which is allowed to pass through thefihn 102 will be proportional to the light passed through the screen 78.and therefore proportional to the position of the mirror 75. This lightfalling upon the photo electric cell 117 will produce a varial ion incurrent passing through thisy cell which will be similar to the currentpassing in the coil of the galvanoineter Yi3 and therefore the resultantcurrent. produced by the vibrating systems 12. This modulating currentthen fed through the primary windings of the transforn'iers 122 to 126and acts upon the wave filters 130. These filters operate so as toselect out definite frequencies` for example, the filter shown at 130could be tuned to the -frequency of the tuning fork 51 and thesuccessive wave filters tuned to the frequencies of the successivetuning forks. In this way if a certain perforation in the paper strippasses over a hole in the tracker bar it will have impressed upon thesensitive film a variation in light intensity proportional to thefrequency of the correspondingl tuning fork, and wher; this film pasesin front of thc pirate elevati ic cell it wilt set up correspondingrvibrations which will be selected out by thiA proper wave filter u". lwill operate the corrcspoinlng relay, for each hole in the tracker barwill correspond to one of the relays 133. 12S-1* etc. which contiol theswell shutters, notes and stop action tf' the pipe organ. In this waywhen the film is passed through the motion icture projector it willcause certain of t e relays to be operated so as to reproduce'the musiccut on the paper strips 21 and 22 and will thus keep the playing of theorgan in synchronism with the showing of the film.

The modified form of this invention shown in Fig. 4 of the drawings,comprises a player mechanism 160, a driving means 161 for operating thelplayer mechanism, a control means 162 for controlling the operation ofthe driving means 161 and a moving picture projector 163 for projectingthe pictures, and also for co-operating with the control mechanism 162for controlling the driving means 161.

The player mechanism 160 consists of two rolls 165 and 166 mounted forrotation in a frame work 167. Wound upon the rolls 165 and 166 is astrip of perforated paper 168, the perforations of which control theplaying of a pipe organ in a well-known manner. At the right hand edgeof the paper strip 168 is a row of perforations 170 which at suitabletimes pass in front of a hole 171 located in a tracker bar 172. The hole171 is connected by a ipe 173 to a primary pneumatic 174, whic when thehole is open to the atmosphere, closes a circuit between two terminals175 and 176.

The roll 166 is provided with a shaft 178 to the end of which is secureda bevelled gear 179 meshing with .a bevelled pinion 180 which is looselymounted on an arm 180 which is carried by the shaft of a motor 1 81. Thebevelled pinion 180 in turn meshes with a bevelled gear 182 which iscarried by the shaft of an electrical repeater 183 which may be of anywell-known and standard con-.

struction. The shaft of the repeater 183 is hollow so that the shaft ofthe motor 181 may freel pass through it. The ends of field windsings ofthe motor 181 are connected to terminals 185 and 186, and the armaturebrushes are connected to terminals 187 and 188. The terminal 185 isconnected by a conductor 190 to one pole of a battery 191, the otherpole of which is connected by a conductor 192 to the terminal 186. Theterminal 187 is connected by a conductor 193 to the righthand armatureof a relay 194. The left hand armature of the relay 194 is connected bya. conductor 195 to the terminal 188. The conductor 193 is connected bya conductor 196 to one armature of a double relay 197, the otherarmature of which is connected by a conductor 198 to the conductor 195.The armatures of the relays 194 and 197 are held in the position shownwhen the relays are deenergized by means of' springsA 200 and 201, resectively. A conductor 202 interconnects the ack contacts of the lefthand armatures of the relays 194 and 197.

The controly mechanism 162 consists of two solenoids 203 and 204 whichare provided With cores 205 and 206, the lower ends of which areconnected to plungers in suitv able dash pots 207 and 208 which are ofsuch construction that they allow the plungers to move downward rapidlyand upward slowly. Secured to the upper ends of the cores 205 and 206are cross arms 209 and 210. These cross armsare held in their retractedpositions as shown by means of springs 211 and 212. Engaging the arm 209are three contacts 215, 216 and 217, and engaging the arm 210are threecontacts 218, 219 and 220. When the arm 209 is moved to its lowestposition it engages two contacts 222 and 223 and when the arm 210is inits lowest position it engages two contacts 224 and 225. The contacts217 and 224' are connected togetherkby the conductor 226, and thecontacts 218 and 223 are connected together by a conductor 227. Thecontacts 216 and 219 are connected together by a conductor 228 and toone pole of a battery 229. The contact 215 is connected b a conductor230 to one end of a winding o the solenoid 231, the other end of saidwinding being connected by a conductor 232 to the battery 229. Thecontact 220 is connected by a conductor 233 to one terminal of a windingof the solenoid 234, the other end of the winding of which is connectedby a conductor 235 to the battery E229. The solenoids 231 and 234 areprovided with movable cores 237 and 239 arranged so that when therespective solenoid is` energized each catches the respective arm 210 or209. The cores 237 and 239 are providedwith springs 240 and 241respectively which move them out of engagement with the arms when thesolenoids are de-energized. The contact 222 is connected by a conductor243 to one end of the windin of the relay 197, the other end of the wining of which is connected by a conductor 244 to the conductor 232. Thecontact 225 is connected by a conductor 245 to one end of the winding ofthe relay 194, the other end of which is connected'by a conductor 246 tothe conductor 244.

One end of the windin of the solenoid 203 is connected by a con uctor250 to the terminal 175. The terminal 176 is connected by a conductor251 to one pole of a battery 252, the other pole of which is connectedby the conductor 253 to the other end of the winding of the solenoid203. One

end of the winding of the solenoid 204 is f conductor 259 to theconductor 251. The brushes 256 and 258 press against a disc ofinsulating material 261 secured to the handle 262 of the moving picturemachine. Inlaid in the insulation 261 is a segment of conductingmaterial 263 which intermittently closes the circuit between the brushes256 and 258. Rigidly secured to the outside of the disc of insulation261 is a bevelled gear 265 which meshes with a bevelled pinion 266secured to the shaft 26T of an electric motion transmitter Thetransmitter 268 is connected bv a four-wire cable 269. shownscizvinriticaliy, to the repeater 283. Inserted in one of the wires ofthis cable is a battery 270.

In the operation oi the form oi' the irven ion shown :fn Fig, 4. thepaper strip 168 is. set in an initial point at the tim.A the film inth#l motion picture projector 1.63 is at its starting place. As thehandle 262 turned by the operator to cause the motion picture to beprojected upon the screen it will rotate yhe shaft 267 of thetransmitter 268 which will transmit this moti .n to the repeater 183,thus driving the bevelled gear 182 and by means of the bevelled pinion160 the bevelled gear 179. This causes the shaft 178 to be rotated, thuswinding up thc strip-of perforated paper 169 on the roll 166. The speed:it which the roll 166 is turned will therefore be proportional to thespeed with which the handle 262 rotated so that the lilm in the motionpicture camera and the paper strip 268 will be moving in synchronism.Due. however, to the .stretching of the paper and other inequalities inthe mechanism it is probable that the paper strip 168 will start to runslightly faster or slightly slower than the proper rate to keep insynchronism with the motion picture iilm. If the paper strip 168 ismoving at its proper rate a perforation 170 will come opposite the hole171 at the same time that the contact segment 263 closes the circuitbetween the brushes 256 and 258. This will close the circuit from thebattery 252 through the conductor 259, brush 258, segment 263. brush256, along conductor 255 through solenoid 204 back to the battery 252 atthe same' time that the circuit is closed from this battery through theconductor 251, primary pneumatic 174, conductor 250, solenoid 203, `backto the battery 252. These two solenoids will then be energizedsimultaneously thus pulling down the two arms 209 and 210 at the sameinstant, and since contacts 216 and 219 are opened the circuits ofthe'relays 194 and 197 are opened, and these relays cannot be energizedto cause the speed of the driving mechanism to be modified. As soon asthese arms move down from the position shown they will break thecircuits through the two solenoids 234 and 231, thus allowing thesprings 241 and 2.1.0 to move the cores outwardly so that when thesolenoids 203 and 204 are deenergized by the paper strip 168 moving overthe hole 171 and the segment 263 moving out of engaement with a brush258, the arms 209 and 210 will be allowed to move upwardly under theaction of the springs 211 and 212, retarded by the dash pots 207 and 208until they will have assumed their initial positions as shown in Fig. 4at which time the solenoids 234 and 231 will be again energized. movingtheir cores into the position shown in Fig. 4.

lf the paper stiip i692 should be moving .slightly faster than itsproper rate one of the perforatious 170 wili come opposite the hole 171before the segment 163 closes the circuit between the brushes 25al and256. This will cause the solenoid 203 to be encrgized while 204 remaidta-energized, thus pulling down thA arm 2 which snaps by the score 239of the soleniiiiil 234 and is held in its` lower-most position. closingthe circuit between contacts 223 and 222. thus allowing current to passfrom the battery 229 through conductor 228. arm 219. conductor 227, arm209. conductor 243. relay 19'?. (.onduct'or 244, back to the battery229. thus energizing the relay 197 which attracts its arn'iatures. Thiscloses the circuit from the battery 191 to the armature terminals 187and 1.88. thus causing the motor 181 to be rotated in such a manner asto cause the pinion E80 to be revolved about the axis of the motor 181in the same direction as the bevellcd gea i 182 which will slow down themotion of the bevelled gear 179 and therefore slow down the motion ofthe roll 166. Tlis will continue until the segment 263 has engaged thebrushes 258 and 256 which will energize the solenoid 204, pulling downits arm 210. This will break the circuit through the magnet 197 and alsothrough the solenoid 234. whose core will be moved to the left, thusreleasing the arm 209 which will move upward under the action of thespring 211, this motion being retarded by the dash pot 207 until itreaches its uppermost position. Before the arm 209 reaches its uppermostposition the segment 263 will have moved out of engagement with thecontacts 256 and 258, thus deenergizing the solenoid 204 which willallow the arm 210 to move upward under the action of the spring 212,this motion being slowed down by the dash pot 208. The core 237 of thesolenoid 231 will not have engaged the arm 210, as the circuit throughthis solenoid will be open due to the arm 209 being out of engagementwith the contact 215. The arm 210 will continue upward until it reachesthe position shown in Fig. 3, at Vwhich time the mechanism is again setin its initial position, and should the paper strip 168 be againslightly in advance of its proper positlon this action will be repeated.

If the paper strip 168 should be moving slightly slower than its properrate the contact`263 will close the circuit through the solenoidA 204before the perforation 170 closes the circuit through the solenoid 203.This will cause the arm 210 to be moved downward until it engages thecontacts 224 and 225. It will be held in this position by the core 237of the solenoid 231 and w1ll cause the relay 194 to be energized, thusclosing the circuits from the battery 191 to the armature terminals 188and 187 which will reverse the direction of current in the armature, andcausing the motor 181 to be rotated in the opposite direction so as-totend to increase the speed of the bevelled gear 179, thus increasing thespeed of the paper strip 168 so as to bring 1t up to its properposition. This continues until the perforation 170 has caused thesolenoid 203 to be energized which pulls down the arm 209, thus breakingthe circuit through the relay 194, thus stopping the motor 181. The twoarms 210 and 209 then return to their initial positions as previouslydescribed.

When the two relays 194 and 197 4are deenergized their left-handarmatures are connected together by means of the conductor 202, thusshort circuiting the armatureof the motor 181 which will tend to holdthe arm 180 in a fixed position so as not to affect the differentialgears 182 and 179, thus allowingr the repeater 183 to transmit itsmotion without change of speed to the shaft 178. It will be seen fromthe foregoing description that if the paper strip 168 is run ning at itsproper speed both solenoids 203 and 204 will be energized simultaneouslyand no modification will be effected by the differential 182, 180, and179. If, however, the paper strip is running faster than lts properspeed this differential will tend to slow down its motion and the timeduring` which the differential is made effective will be determined bythe interval of time between the moment that the circuit is closed bythe primary act-ion 174 due to a perforation 170 passing in front ofhole 171, and the moment at which the segment 263 closes the circuitbetween the contacts 256 and 258. The time which the' differential actsis therefore proportional to the amount that the paper strip168 iseither ahead or behind its proper position which will thus tend to bringit rapidly' into synchronism with the film of the moving pictureprojector 163.

Figure 5 shows the same mechanism as that depicted in Fig. 2 withthegaddition of the necessary apparatus for producing a series ofmusical chords or other tones in the same key as the music, if the filmis inadvertently broken. yThis additional apparatus consists of aplurality of 7transformers 501, 502, 503, etc., the primary windings ofwhich are in series with the primary windings of the ltransformers 121,122, etc. The secondary windings of-the transformers 501, 502, 503,etc., are connected to suitable wave filters which control relays 505,506, 507, etc. in a manner similar to that described in connection withthe circuit 130, 131 and 132. The relays 505, 506, 507, etc., controlthe operation of t-he solenoids 510, 511, 512, etc. The return circuitfrom these solenoids includes a conductor 515 which is connected to oneend of the winding of a solenoid 516 the other end of the winding ofwhich is connected to one pole of a batery 517, the other pole of whichis connected by a conductor 518 to the armatures of the relays 505, 506,507, etc.

Located adjacent to the solenoids 510, 511, 512, etc. is a slidableframe 520 which may move freely in a transverse direction on astationary frame work 523. Mounted on the stationary frame work 523 is apneumatic cylinder 525, the supply of air to which is controlledV by avalve 526 operated by the solenoid 516. The valveV 526 is connected by apipe 527 to a supply of air under pressure (not shown). Slidably mountedin the cylinder 525 is a piston 530 which is connected to one end of apiston rod 531 the other end of which is secured'to the sliding frame520. Located in the cylinder 52,5 is a coiled spring 531 which tends tomove the piston 530 and the frame 520 to the left. Mounted upon thesliding frame 520 are two spools 532 and 533 over which passes a stripof perforated paper 534. The shaft which carries the lower spool 533 isprovided with an extension 535, the left-hand end of which is squaredand fits snugly butslidably in a collar 536 which is carried by theshaft of a motor 537 which is mounted on the frame work 523 and which isdriven by a battery 538, the circuit of which is controlled by one sideof a double pole switch 539. Rigidly mounted in the fixed frame work 523is a tracker bar 540 provided with a plurality of holes541 which areconnected by tubes 542 to a relay mechanism 545 which controls the l.nism 545 passes along a conductor 550 and by a flexible conductor 552to a Contact 553 mounted on a block of insulation 554. A contact 555 isalso mounted on the insulation 554 and is connected by a flexibleconductor 556 to one pole of the double pole switch 539 the other sideof which is connected by a conductor 558 to the conductor 140.

The cores of the solenoids 510, 511, 512, etc., are provided at theirupper ends with a segment of conducting material 560 which is insulatedfrom the core by a strip of insulation 561. When the solenoids areenergized the, segments 560 are moved up into the path of the contacts553 and 555. The cores arenormally held in the position shown by springs562.

In the transmitting apparatus shown in F 1g. 1 a certain group of holeson the tracker bar 27 are used for denoting the key in which the musicis being played, so that when the music is being played in a given key,for example, that of G, the group of perforations in the paper strip 22will continuously uncover the hole in the tracker bar 27 which willoperate the relay, mechanism 11 to cause a given vibrating system 12, tobe set in action, thus producing a given frequency of vibration which aspreviously described is combined with the other vibrations produced toform the curve on the film 16. For each key in which the music may beplayed there will be a given frequency which will be lproduced when themusic is played in that When the film is run through the motion pictureprojector 101, the curve will cause the proper circuit to be energizedwhich in turn will close the proper relay of which, for example, is 505.This` will close the circuit through the solenoid 510, thus causing itscore to be lifted and at the saine time cui-- rent will pass through theconductor 515 and energize the solenoidl 516, thiis allowing air toenter the cylinder 525 which will cause the piston 530 to be moved tothe right,f'thus shifting the sliding frame work 520 to the right untilthe contacts 553 and engage the segment 560 of the solenoid 510, thusstopping the motion of the sliding frame 520. In this position, thesliding frame will be so located that. the music which is cut in thepaper strip 534 will be playediii the key G. As long as the switch 539is open, however, this music can not be played as the relay mechanism545 will be inoperative. If the moving picture fil-m 102 should break,the operator will immediately close the switch 539 which will thus throwin the relay mechanism 545 and the organ will be played from the paperstrip 534 in a similar manner as that described in Fig. 2.

When the film has been repaired, andthe machine started in operationagain, the operator will open the switch 539, thus disconnecting therelay mechanism 545 which will stop the playing of the organ from thepaper strip 534 and will allow it to be played again from the film 102as already described.

If the key in which the music is being played is changed the relay 505will be deenergized thus breaking the circuit through the solenoids 510and 516. This will shut off the supply of air to the cylinder 525 andwill allow it to exhaust to the atmosphere. The spring 531 will thenreturn the sliding frame 520 to its initial position at the left. Assoon as another relay, such for example, 507 is energized, denoting thatthe music is played in another key, say for example the key of C, thesolenoids 512 and 516 will be energized and the frame work 520 will bemoved, as previously described, into 'a position which will cause themusic to be played in the key ot C.

In the construction of the foi'in of the invention shown in Figure 5 thepaper strip 534 is made of sufficient width so that when it is in anyofthe playing positions its edges will entirely coverv the row of holes541 so that these holes will only be exposed when perforations in thepaper 534 come in front of them. y

It is evident that this modified form of the invention may be soconstructed that the frame 520 is stationary. and that the tracker bar540 may be made movable by connecting it to the piston rod 531 andbylocating the contacts 551 and 555 upon the tracker bar, and placing thesolenoids 510, 511 and 512 etc. in a suitable position. If this weredone it would be necessary to make the tubes 545` of some flexible.material such as rubber tubing.

The system shown in Figure 6 is a modified torni of the system of Figure2 and coniprises a standard typel of motion picture projector 101provided with a film 102 which is rolled upon spools 103 and 104 andpasses over a toothed drinn 105. This drum is provided with a bevelledgear 106 which meshes with a bevelled pinion 107 secured to a shaft 108,the other end of which carries a` similar bevelled pinion 109, meshing'with a bevelled gear 110 rigidly secured to the crank 111 whichoperates the projector 101. v

Located adjacent to the film 102 is a suitable source of illumination115, the light from which is focused by means of a lens system 116 onthe film 102 on the other side of which is located a photo electric cell117` one terminal of which is connected to .a battery 119, the otherterminal of which is connected by a conductor 120 to the primarywindings of a plurality of transformers 121 to 126, etc. connected inseries. The return circuit from these transformers includes a conductor127 to the photo electric cell 117. The secondary windings of thetransformers 121 to 126 are connected to the input circuits of anamplifying system 132, the output circuits of which control relays 133to 138, etc. The armatures of these relays are connected together and toone pole of a battery 601, the opposite pole o'f which is connected tothe windings of a plurality of relays 602 to 607, etc., the same innumber as the relays 133 to 138. Each ot' the windings of the relays 602to 607, etc., is connected by means of an individual conductor to a.front contact of a relay on the train of relays 133 to 138, etc., andthus the relay 602 is controlled by the relay 133, relay 603 by relay134, relay 604 by relay 135, relay 605 by relay 136, relay 606 by relay137, and relay 607 by relay 138, respectively. The relays 133 to 138,etc. are of the so-called harmonic type relay, and are provided withweighted or mechanically tuned armatures each tuned to a differentperiod of vibration. The armature operated only when the respectiverelay winding is energized by a current having substantially the sameperiodicity.

Each of the relays 602 to 607, etc. is provided upon its core with acopper slug whereby the said relays are caused to be slow releasing.Consequently, when any of the said relays is operated due to theenergization of its respective tuned relay of the train 133 to 138,etc., it will not respond to momentary interruptions of its circuitcaused by vibrations of the tuned relay armature,

but will maintain its own 'armature in the operated position independentof such vibrations or fluctuations. The relays 602 and 603 controlcircuits through conductors 142 and 143 extending to the terminals of aswell shutter motor 301 which controls the actions of the swell shuttersof the organ in a manner hereinbefore described. The swell shutters arecontrolled by relays (S04, 605 in a manner already described, andsimilarly the primary stop action 11 is controlled by relays 606 and 607over conductors 153 and 154 as has beeli described.

It will be understood that in practice a sufficient number of sets ofband filters, amplifying circuits, relays, etc. each duplicates of thoseshown by way of illustration, will be provided to control all thecircuits of the swell pedals, keys and stop action of the organ.

The structure of Figure 6 may be elnployed in connection with that ofFigure 3 in the same manner as was Figure 2 previously described, thefigures being arranged with Figure 6 immediately to the left of Figure3. In the operation of a system including Figures 6 and 3, the filmhaving been prepared by means of the apparatus of Figure 1 as has beendescribed, the film is put into the projector 101 and it is fed from theroll 103 in an intermittent manner by the operation of the crank 111.This crank by means of the gear train 110, 109, 107 and 106 causes theuniform rotation of the drum 105. This feeds the film 102 at a uniformrate in front of the beam of light produced by the light source 115,this beam of light being focused upon the narrowy strip on the filmcontaining the record produced by the beam of light reflected from themirror 75. The amount of light which is allowed to pass through the film102 will be proportional to the light passed through the screens 78, and

f therefore proportional to the position'of the be similar to thecurrent passing in the coilV of the galvanometer 13 and therefore theresultant current produced by the vibrating systems 12. This modulatingcurrent is then fed through the primary windings of the transformers 122to 126 and acts upon the respective tuned relay of the relay train 133to 138, etc., through the associated amplifier such as 132. These tunedrelays respond only to predetermined frequencies in each case and in thepresent instance are each tuned to one of the frequencies of the tuningforks employed in the vibrating systems 12 of Figure 1. For example, therelay 133 is preferably tuned to the frequency of the tuning fork 51 ofFigure 1 and the successive relays of the group of tuned relays tuned tothe frequencies of the successive tuning forks. In this way if a certainperforation in the paper strip passes over a hole in the tracker bar itwill have impressed upon the sensitiv-e lilm a variation in lightintensity proportional to the frequency of the corresponding tuningfork, and when this film passes in front of the photo electric cell itwill set up corresponding vibrations which will be selected out by theproper wave filter and will operate the corresponding relay, for eachhole in the tracker bar will correspond to'one of the relays 133, 134,etc. which by means of the associated slowly releasing relays 602, 603,etc., control the swell shutters, notes and stop action of the pipeorgan. In this way when the film is passed through the motion pictureprojector it will cause certain of the relays to be operated so as toreproduce the music cut on the paper strips 21 and 22 and will thus keepthe playing of the organ in synchronism with the showing of the film.

While I have shown and described and have pointed out in the annexedclaims certain novel features of my invention, it will be understoodthat Various omissions, substitutions and changes in the forms anddetails of the device illustrated and in its operation may be made bythose skilled in the art without departing from thev spirit of myinvention.

Having thus described my invention, what I claim is 1. The method ofproducing music which consists in registering photographically on a filma series of light waves of varying intensity according to the music tobe played,

vtransmitting through such film a beam of light so as to effect aphotosensitive cell, producing thereby a series of electricaloscillations of predetermined frequency, producing independently thereofa musical tone, and controlling the emission of the musical tone by saidelectrical oscillations.

2. The method of producing music which consists in registeringphotographically on a film a series of light waves of varying inw"....www auw-.M ...ma

tensity according to the music to be played transmitting through suchfilm a beam o light so as to effect a photosensitive cell, producingthereby 'a series of electrical oscillations of redetermined frequency,producing indepen ently thereof a musical tone of a relatively differentfrequency, and controlling the emission of the musical tone by saidelectrical oscillations.

3. In a musical instrument, the combination of means for registering ona sensitive photographic film a series of light waves of varyingintensity according to the music to be played, means for transmittingthrough said film a beam of light, a photo-sensitive cell responsive tovariations in intensity of said transmitted beam of light, means forproducing a plurality of sounds selectively, a circuit controlled bysaid photo-sensitive cell, said circuit including a plurality ofelectrical filteringl devices arranged to actuate said sound producingmeans respectively for controlling the production of sound, saidelectrical filtering devices being selectively responsive to electricalenergy7 of predetermined frequency.

4. The method of producing sound which consists in registeringphotographically on a film a series of light waves of varying intensityaccording to the sound to be played, transmitting through such film abeam of light so as to effect a photosensitive cell, producing thereby aseries of electrical oscillations of predetermined frequency, producingindependently thereof a series of sounds, and controlling the emissionof the sound by said electrical oscillations. q

5. The method of producing sound which consists in registeringphotographically, on a film a series of light waves of varying intensityaccording to the sound to be played, transmitting through such film abeam of light so as to effect a photosensitive cell, producing thereby aseries of electrical oscillations of predetermined frequency, producingindependently thereof a series of sounds of a, relatively differentfrequency, and controlling the emission of the sound by said electricaloscillations.

6. A system of producing sound comprising means for producing lightwaves of varying intensity, a photo sensitive cell controlled by saidWaves, a circuit including said cell and controlled thereby to produce aseries of electrical oscillations, and means including a sourcey ofsound having a pitch independent of the frequency of the variations inintensity of the light, said means being controlled by the electricaloscillations of predetermined frequency.

7. In an instrument for producing sound, the combination of an automaticmusic roll having perforations, pneumatic relay mechanism selectivelycontrolled thereby, a plurality of sources of electrical oscillations ofrelatively different frequency respectively controlled by said pneumaticrelay mechanism, a mirror galvanometer actuated by said oscillations tocontrol a beam of light, a light sensitive element in the path of saidlight beam, and means controlled by said light sensitive element toroduce music in aclcordance with the per orations in said ro l.

8. In an instrument for producing sound, the combination of an automaticmusic roll having perforations, pneumatic relay mechanism selectivelycontrolled thereby, a plurality of sources of electrical oscillations ofrelatively different frequency respectively controlled by said pneumaticrelay mechanism, a mirror galvanometer actuated by said oscillations tocontrol a beam of light, a light sensitive element in the path of saidlight beam, an organ, and means controlled by said light sensitiveelement to actuate said organ in accordance with the perforations insaid roll.

9. In a sound recording system, the combination of an automatic musicroll having perforations, a plurality of pneumatic relays selectivelycontrolled thereby, a corresponding plurality of sources of electricaloscillations of relatively different frequency controlled by saidpneumatic relays respec- 9 tively, a mirror galvanometer actuated bysaid oscillations to control a beam of light, a light sensitive elementin the path of said light beam, a musical instrument, and meanscontrolled by said light sensitive element to actuate the musicalinstrument in accordance with the perforations in said roll.

10. In an instrument for producing sound. the combination of anautomatic music roll havin'g perforations, pneumatic relay mechanismselectively controlled thereby, a plurality of sources of electricaloscillations of relatively different frequency respectively controlledby said pneumatic relay mechanism, a mirror galvanometer actuated bysaid oscillations to control a beam of light, a light-sensitive elementin the path of said light beam, and means controlled by said lightsensitive element to roduce music in aezlordance with the perfbrationsin said ro 11. In a sound recordin system, the combination with soundrecordging means includ; ing an automatic music roll havingperforations, a plurality of pneumatic relays selectively controlledthereby, a corresponding plurality of sources of electrical.oscillations of relatively different frequency controlled by saidpneumatic relays re ectively, a mirror to control a beam of slight, amagnet actuated by said oscillations to'operate the mirror, and a lightsensitive element in the path of said light. beam, of reproducingmechanism controlled b said light sensitive element including a purality of electrical lltl filters each tuned to the frequency of one ofsaid electrical oscillations respectively, an amplifier in the output ofeach of said filters, an electroma etic device controlled by .each ofsaid amplifiers, and a plurality of organ actions controlled by saidrelays respectively.

12. In a sound recording and reproducing system, the combination 'withmeans for recording a musical composition on a photographic film, ofreproducing mechanism including a source off'musical sound ofpredetermined pitch and light sensitive means controlled by said iilmarranged to control the operation of the sound source to reproduce themusical composition. V;,

13. In a sound recording and reproducing system, the combination wthmeans' for recording a musical composition on a light sensitiverecording film, rof reproducing mechanism including an organ, means forv transmitting a beam of light through the filni on which the record ismade, and means responsive to variations in intensity of saldtransmitted light beam to control the o ration ofsaid organ to reproducethe musical composition.

14. In a sound recording and reproducing system the combination withmeans for 0recording a musical composition written in a predeterminedkey of the musical scale, includi'ng means for modifyin a photographicfilm to make the' recor of producing mechanism including agsource omusical sound, light sensitive tmeans controlled 'by said film, andmeans actuated by said light sensitive means for causing the soundsource to reproduce the musical composition in a relatively diilerentkey of the musical scale.

15. In a sound recording and reproducing system the combinationwithmeans for recording a musical composition written in a:predetermined key of the musical scale, including means for modifying aphotographic film to make the record, of pro ucing mechanism includingan or an, light sensitive means controlled by s ai film, and meansactuated by saidl light sensitive means for causing the organ toreproduce the-musical composition in a relatively diiferent key ofthemusical scale.

16. Apparatus for recording music comprisinga light sensitive element, asource of light, a mirror galvanometer arranged to control a beam oflight emanating from said source so as to impinge upon said lightsensitive element, a plurality of sources of oscillatory current for'actuating said galvanometer, and means including a perforated musicsheetfor selectively controlling said i sourcespfcurrent. y

' f 17.1Apparatus for recording music coincontrol a beamv o prising alightsensitive element, a source of light, 'a mirror galvanometerarranged to light .from said source so as to impinge upon. .said'lightsensitive eletrolling said source of current.

19. Apparatus for recording music comprising a light sensitive element,a source of light, an ielectromagnet, light reflecting means controlledby said lelectromagnet and arranged to control a beam of light emanatingfrom said source so as to im inge upon Said light sensitive element, a purality of sources of oscillatory current for actuating saidelectromagnet, and means including a perforated music sheet forselectively rendering said sources of current effective.

20. Apparatus for recording music comprising in combination, a lightsensitive element, a source of light, and means for variably impressinglight emanating from said source upon the light sensitive elementincluding a perforated music sheet, a plurality of pneumatic relaysselectively controlled by said sheet and a corresponding plurality Vofsources of oscillatory current, each of said sources including a tuningfork, for actuating said impressing means.

.com osition including a paper roll having per orations corresponding'to musical sounds required in the production of the composition, aplurality-of sources of oscillatory currents of different frequenciesrespectively rendered effective by perforations in the note sheetrespectively', means actuated-by waves .produced by said current forvariably controlling 1i ht, and a li ht sensitive element arranged inthe ath o the controlled light for recording t e light variations, thefrequencies ofsaid currents being inde ndentof the wave fimpency of themusical sounds recorded ythe y. f

^21. Apparatus for recording music includ-` uency of current produced by23. Apparatus for the production of a musical composition including alight sensitive element having an image thereon, a source of lightpositioned to one side of said element, a photo electric cell on theopposite side of said element and responsive to variations in saidimage, a musical instrument, a player action for operating saidinstrument to produce musical sound in a desired key, and meansselectively controlled by the photo electric cell for actuating saidplayer action to select the key in which the music is to be played.

24. Apparatus for the production of a musical composition including afilm having an image thereon, a source of light positioned to one sideof said film, a photo electric cell on the opposite side of said filmand responsive to variations in said image, a nuisical instrument, aplayer action for operating said instrument to produce music, and meanscontrolled by the photo electric cell for moving said action into adesired active position.

25. In a sound reproducing system, a musical instrument, a source ofvarying light rays and means operable in response to variations in saidlight rays for controlling said instrument.

26. In a sound reproducing system, a musical instrument, a source oflight rays, means for varying said light rays at different frequenciesand means dependent upon the frequency of said variations forcontrolling the emission of said sound waves from said instrument.

27. In combination with a musical instrument a photographic film, meansfor controlling said instrument by the image on said film and meanscontrolled by an interruption of said film for causing said musicalinstrument to produce a predetermined group of notes.

28. In combination with a musical instrument a remote control thereforcomprising a photographie film and means responsive to a discontinuanceof said film for causing a predetermined group of notes to be played bysaid instrument and means whereby said notes are selected in the samekey as that of the music being played prior to such interruption.

29. In combination with a musical instrument a remote control therefor,means responsive to said remote control whereby said musical instrumentis caused to play music in a predetermined key and means operable uponfailure of said remote con'trol for causing said musical instrument toplay a sequence of notes in said key.

30. In combination with a musical instrument a remote control therefor,and means operable in response to abnormalities in said remote controlfor causing said instrument to continue playing preselected notes.

31. In combination with a musical instrument a remote control therefor,and means operable in response to abnormalities in said remote controlfor causing said instrument to continue playing preselected notes, saidnotes being 1n the same key as that played prior` to such abnormality.

In testimony whereof I hereunto affix my signature.

JOHN HAYS HAMMOND, Jn.

